Apparatus and method for the insertion of a medical device

ABSTRACT

An apparatus and method for insertion of medical devices is disclosed. One embodiment, includes an access tube with a retention portion disposed at a distal end. The retention portion is reconfigurable between first and second configurations of reduced and increased lateral extent. A trocar can be moveably disposed within the access tube, which can be movably disposed within an overtube. One method of the invention includes inserting the trocar and access tube through a patient&#39;s body wall where the retention portion is configured from a reduced to an increased lateral extent. An overtube can be inserted around the access tube through the body wall where the retention portion can be received through a slot defined by the overtube. The retention portion can be returned to reduced lateral extent. The access tube can be removed and the medical device can be inserted within the overtube.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.09/837,481, filed on Apr. 19, 2001 now U.S. Pat. No. 6,743,207, which isincorporated herein in its entirety by reference thereto.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an apparatus and method foruse in the percutaneous insertion of medical devices. More specifically,the present invention relates to a gastro-intestinal tube placementdevice which includes a trocar, an access tube having an internalretention portion at its distal end for engaging an internal gastricwall, and an overtube.

2. Description of the Related Art

Medical practitioners utilize a variety of gastro-intestinal devices toaccess the gastro-intestinal tract. One type of gastro-intestinaldevice, the gastro-intestinal tube or gastrostomy tube, is widely usedwith patients who require catheterization for the purposes of, forexample, delivering food or medication to the gastro-intestinal tract,draining the tract, or creating a surgical port.

Medical practitioners often use Percutaneous Endoscopic Gastrostomy(PEG) techniques, such as those described in U.S. Pat. Nos. 4,861,334;4,900,306; and 5,080,650, to place tubes within the gastro-intestinaltract. These techniques typically involve a trans-oral approach ofplacing a gastro-intestinal tube in the patient's mouth and snaking itdown the esophagus, into the stomach, and out the abdominal wall. Othertechniques involve percutaneously inserting a tube into the stomach fromoutside of the abdominal wall by sliding the tube over a guidewire.

Practitioners have encountered numerous problems with the trans-oraltechniques, which are complicated and cumbersome, often requiring morethan one person to perform. Many of the problems are caused by draggingthe gastro-intestinal tube through the anatomy. Problems such as patientdiscomfort, esophageal trauma, internal bleeding, and gastro-esophagealreflux condition, are caused or exacerbated by dragging of thegastro-intestinal tube through the esophagus. In addition, the risk ofabdominal infection is increased due to the dragging of thegastro-intestinal tube through non-sterile areas such as the mouth andesophagus prior to placing the tube in the gastric and abdominal walls.

Practitioners have also experienced problems with techniques involvingthe percutaneous insertion of a tube. Some such problems are due to thefact that there is often no retention of the stomach wall's positionwith respect to axis of insertion. The stomach wall is often pusheddistally during insertion, causing it to drift away from the abdominalwall. As the gastric wall drifts, the site chosen for tube placementwithin the gastric wall is lost. The lack of retention of the gastricwall makes dilation of the abdominal and gastric walls difficult, andallows for unintentional and undesirable pneumoperitoneum.

Other problems experienced with percutaneous insertion techniques arecaused by the sequential insertion of dilation devices that is ofteninvolved. The abdominal wall, which is not particularly suited tosequential dilation, is often traumatized during the process. Inaddition, the sequential passage of devices prolongs the time needed toperform placement, and potentially leads to undesirablepneumoperitoneum.

Therefore, it is desirable to provide an improved apparatus and methodfor the placement of gastro-intestinal tubes, and more generally, theplacement of any internal medical device.

SUMMARY OF THE INVENTION

In an embodiment, a medical device insertion apparatus includes anaccess tube defining a central lumen and a retention portion disposed ata distal end of the access tube. The retention portion is reconfigurablebetween a first configuration of reduced lateral extent and a secondconfiguration of increased lateral extent. A trocar is moveably disposedwithin the central lumen of the access tube. The access tube is movablydisposed within a central lumen of an overtube.

In an embodiment of a method of the present invention, the methodincludes the steps of inserting the trocar and access tube through abody wall of a patient, where the trocar is disposed within the accesstube and where a retention portion disposed at a distal end of theaccess tube is configured in a first configuration of reduced lateralextent. The retention portion is then configured in a secondconfiguration of increased lateral extent. The trocar is removed fromthe access tube. An overtube is inserted around the access tube andthrough the body wall, where the access tube is received within acentral lumen of the overtube and where the retention portion isreceived through a slot defined by the overtube. The retention portionis returned to the first configuration of reduced lateral extent. Theaccess tube is removed from the central lumen of the overtube and themedical device is inserted within the central lumen of the overtube andthrough the body wall. The overtube is then removed.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features of the invention will best be appreciated bysimultaneous reference to the description which follows and theaccompanying drawings, in which:

FIG. 1 is a side view, partially in section, of an embodiment of themedical device insertion apparatus of the present invention;

FIG. 2 is a side view, partially in section, of the embodiment of FIG. 1with the retention portion in its deployed position;

FIG. 3 is a side view, partially in section, of the embodiment of FIG. 1with the overtube disposed around the access tube with the retentionportion in its deployed position;

FIG. 4 is a side view, partially in section, of the embodiment of FIG. 1with the overtube disposed around the access tube with the retentionportion in its deactivated position;

FIG. 5 is a side view, partially in section, of the embodiment of FIG. 1with the access tube removed from the overtube and with agastro-intestinal tube inserted through the overtube;

FIG. 6 is a perspective view of an embodiment of a locking mechanism ofthe trocar and access tube; and

FIG. 7 is a side view, partially in section, of an alternativeembodiment of the medical device insertion apparatus of the presentinvention.

DETAILED DESCRIPTION

An embodiment of the medical device insertion apparatus 1 of the presentinvention, which in an exemplary embodiment will be described as agastro-intestinal tube placement device, is shown in FIG. 1. The deviceincludes a trocar 10, an access tube 12, and a dilating overtube 20. Theplacement device 1 is capable of engaging the patient's internal gastricwall during insertion, thereby preventing the gastric wall from driftingaway from the patient's abdominal wall. The device 1 also allows aphysician to place a gastro-intestinal tube percutaneously, withouthaving to perform sequential dilation which can lead to manyphysiological maladies.

The trocar 10 and access tube 12 of the placement device 1 are formedsuch that they can be percutaneously inserted together as an assemblythrough the abdominal and gastric walls. The trocar 10 can be any of avariety of medical trocars having a distal end which is capable ofpenetrating the abdominal and gastric walls, e.g., a sharp distal end.During the insertion process, the distal end of the trocar 10 is used toinitially penetrate the abdominal wall. The assembly of the trocar 10and access tube 12 is then pushed distally until the assembly hassufficiently penetrated the gastric wall 50. Markings can be made on theouter surface of the access tube 12 to indicate the depth of insertion.

The trocar 10 and access tube 12 preferably have complementary matingparts 22, 24, respectively of a locking mechanism, as can be seen atleast in FIGS. 1 and 6, which prevents those components from moving withrespect to each other during insertion. The locking mechanism ispreferably a twisting hub assembly of the type shown in FIG. 6, but maybe any mechanism for temporarily connecting the trocar 10 and accesstube 12. Prior to insertion, the mating parts 22, 24 are engaged, thuslocking the trocar 10 and access 12 tube together. Once the assembly isproperly in-place within the gastric wall, the mating parts 22, 24 aredisengaged, allowing removal of the trocar 10 from within the accesstube 12.

The access tube 12 of the present invention is preferably formed of twoconcentric, slidable with respect to each other, malecot sheaths 14, 16,which are attached at their distal ends. Additionally, the access tube12 has a retention portion 18 at its distal end, which is capable ofbeing compressed or deactivated during insertion, and deployed oractivated once the access tube 12 is properly placed within the gastricwall. The retention portion 18 can be made of wings such as those on amalecot-type catheter. In its deployed state, the retention portion 18has a lateral extent which is greater than the diameter of thepercutaneous penetration post-dilation. With this increased lateralextent, the practitioner performing the insertion process can pull theaccess tube 12 proximally, causing the retention portion 18 to engagethe internal gastric wall, thereby preventing the gastric wall fromdrifting away from the abdominal wall.

In an embodiment, the distal retention portion 18 is deployed byunlocking mating sections 30 and 32 of outer malecot sheath 16 and innermalecot sheath 14, respectively, and then by moving the outer malecotsheath 16 distally with respect to the inner malecot sheath 14. Thedistal movement of the outer sheath 16 causes the distal portion of theaccess tube 12 to form lateral wings 26, 28, which are similar to thoseof other malecot sheaths. FIG. 2 illustrates the retention portion 18 ofthe access tube 12 in its deployed, or activated, state. Although therecan be any number of wings, such as two wings 26 and 28, the deployedretention portion 18 preferably has a malecot-type shape. The lateralextent of the deployed retention portion 18 is sufficient to provideretention of the gastric wall during insertion of the dilating overtube20.

As mentioned above, the inner sheath 14 and outer sheath 16 preferablyhave mating parts 32, 30, respectively, of a locking mechanism whichallow the sheaths to be attached to each other and thereby avoidrelative movement with respect to each other during initial insertion.This locking mechanism can also be a twisting hub assembly, similar instructure to mating parts 22, 24 of the locking mechanism illustrated inFIG. 6.

Whereas an embodiment of the present invention includes mating sections30 and 32, it is not required that these mating sections be utilized inthe present invention.

After initial insertion is complete and the trocar/access tube assemblyis properly in place within the gastric cavity, as discussed above, thelocking mechanism formed by mating parts 30 and 32 is disengaged, suchas by untwisting the twisting hub assembly if a twisting hub assembly isutilized for the locking mechanism or by pushing the outer sheath 16distally with respect to inner sheath 14 and uncoupling a tapered,frictional engagement form-fitted structure that comprises mating parts30 and 32. The outer sheath 16 is pushed distally to bring theadditional mating locking part 34 of inner sheath 14 into contact withthe mating part 30 of the outer sheath 16. By engaging mating parts 30and 34, the sheaths 14 and 16 are locked in position with the distalretention portion 18 deployed.

Again, any number of various configurations for mating parts, and thusfor locking hubs, can be utilized in the present invention. For example,a slide lock similar to the type used on various handles for temporarylocking of two pieces together relative to each other can be utilized inthe present invention. Additionally, locking hubs such as thosetightened on the outside diameter of various catheters can be used.

The dilating overtube 20 is a tubular structure with a central lumencapable of passing over the access tube 12, with or without the trocar10 within the access tube 12. As can be seen in FIG. 3, during theovertube insertion process, the overtube 20 is advanced distally overthe access tube 12 until it is properly placed within the gastric wall.Preferably, the overtube 20 has slots 21, 22 at its distal end which arecapable of receiving within them the deployed wings 26, 28,respectively, of the distal retention portion 18 when the overtube 20 isdistally advanced over the access tube 12.

The distal end of the overtube 20 is tapered to facilitate advancementof the overtube 20 through the patient's anatomy. The overtube 20 mayalso have a small circumferential groove 23 at its distal end whichcould be grasped by an endoscopic snare. In order to facilitate distaladvancement of the overtube 20 during its insertion, an endoscope havinga snare can be placed within the gastric cavity. The practitionerperforming the insertion process can then pull the snare, causing theovertube 20 to advance distally into the gastric cavity.

Once the overtube 20 is properly placed, the retention portion 18 of theaccess tube 12 is compressed, or deactivated, by unlocking mating parts30 and 34 and moving outer sheath 16 proximally with respect to innersheath 14, as can be seen in FIG. 4. Deactivation of retention portion18 allows removal of the access tube 12 from within the penetration.With the distal portion of the overtube 20 in place within the gastriccavity, as can be seen in FIG. 5, a gastro-intestinal tube 40 can beinserted into the gastric cavity by first placing the gastro-intestinaltube 40 within the central lumen at the proximal end of the overtube 20and then pushing the gastro-intestinal tube 40 distally until it exitsthe distal end of the overtube 20.

The distal dilating tip of the overtube could be comprised such that itcould expand if a device having a larger diameter than that of thedistal dilating tip were required to be inserted through it. Thisexpansion could be achieved by comprising the dilating tip of asemi-flexible material, providing longitudinal slits in the dilatingtip, by utilizing a combination of the these two techniques, or throughother known methodologies.

After the distal end of the gastro-intestinal tube has exited the distalend of the overtube 20, the overtube would be removed by sliding theovertube proximally in relation to the gastro-intestinal tube. Thegastro-intestinal tube remains in position in the gastric cavity due toany number of known retention mechanisms. The gastro-intestinal tube isthen left in place, percutaneously inserted into the gastric cavity.

FIG. 7 illustrates an alternative embodiment of a medical deviceinsertion apparatus 100 of the present invention. In the embodiment ofFIG. 7, the dilating overtube 130 also includes a retention portion 138.Retention portion 138 is included in addition to retention portion 128of access tube 120. Retention portion 138 provides an additionalmechanism for anchoring the overtube 130 within the gastric cavity andmaintaining the relative positioning of the gastric wall 200 withrespect to the abdominal wall 210 during removal of the access tubeand/or passage of a gastro-intestinal tube through the lumen of theovertube.

As can be seen in FIG. 7, retention portion 138 may consist of laterallyextending wings 136, 137 of malecot-type, which may be similar to wings26, 28 of the previous embodiment. Additionally, retention portion 128of access tube 120 may also consist of laterally extending wings 126,127 of malecot-type, which also may be similar to wings 26, 28. Bothretention portion 128 and retention portion 138 are moveable between afirst configuration of reduced lateral extent and a second configurationof increased lateral extent. Retention portions 128 and 138 are movedbetween their first and second configurations in the same manner as wasdescribed for retention portion 18. Similar to the previously describedembodiment, overtube 130 includes slots in its distal end to provide forreceiving the deployed wings of retention portion 128 within them.

In the embodiment of FIG. 7, as in the previous embodiment, trocar 110is movably disposed within access tube 120. Access tube 120 includes aninner sheath 121 and an outer sheath 122. Retention portion 128 isdisposed at a distal end of outer sheath 122. Retention portion 128, inits second configuration, as described above, extends through anaperture, or slots, included in the distal end of overtube 130.

Overtube 130 also includes an inner sheath 131 and an outer sheath 132.Retention portion 138 is disposed at the distal end of outer sheath 132.Retention portion 138, in its second configuration, is disposed distallyof retention portion 128.

Finger grips 123 and 133 are provided on access tube 120 and overtube130, respectively, to aid in medical device insertion apparatus 100.

As described above, in practicing a method in accordance with theprinciples of the present invention, the method includes the steps ofinserting the trocar and access tube through a body wall of a patient,where the trocar is disposed within the access tube and where aretention portion disposed at a distal end of the access tube isconfigured in a first configuration of reduced lateral extent. Theretention portion is then configured in a second configuration ofincreased lateral extent and pulled outward to compress, in anembodiment, the gastric, or stomach, wall against other body tissues,e.g., the abdominal wall. The trocar is removed from the access tube. Anovertube is inserted around the access tube and through the body wall,where the access tube is received within a central lumen of the overtubeand where the retention portion is received through a slot defined bythe overtube. The retention portion is returned to the firstconfiguration of reduced lateral extent. The access tube is removed fromthe central lumen of the overtube, the overtube is pushed inward, in anembodiment, to maintain access as the stomach assumes a normal positionin the body in the absence of being retained by the retention portion ofthe access tube, and a medical device is inserted within the centrallumen of the overtube and through the body wall. The overtube is thenremoved.

The disclosed embodiments are illustrative of the various ways in whichthe present invention may be practiced. Other embodiments can beimplemented by those skilled in the art without departing from thespirit and scope of the present invention. For example, whereas anapparatus and method of the present invention has been described for usein the percutaneous placement of a gastro-intestinal device, e.g., agastro-intestinal tube through the gastric wall, the principles of thepresent invention can be utilized for placement of any type of deviceinto any hollow internal organ. Examples of other hollow internal organsinto which devices can be inserted with the present invention includethe liver, kidney, small or large intestine, bladder, etc.

1. A medical device insertion apparatus, comprising: a trocar; an accesstube disposed around the trocar, the access tube comprising a firstsheath and a second sheath, the second sheath having a retention portiondisposed at a distal end of the second sheath, the retention portionreconfigurable between a first configuration of reduced lateral extentand a second configuration of increased lateral extent by movement ofthe first sheath relative to the second sheath; and an overtube disposedaround the access tube and movable relative to the access tube; whereinthe overtube is adapted for insertion through a tissue wall and theovertube comprises at least one slot through a side wall of theovertube, and wherein, when the retention portion of the second sheathis in the second configuration of increased lateral extent, theretention portion is receivable within the at least one slot.
 2. Themedical device insertion apparatus of claim 1 wherein the trocarincludes a connector portion at a proximal end thereof and wherein theaccess tube includes a mating connector portion at a proximal endthereof, the connector portion couplable with the mating connectorportion such that when coupled the trocar is rigidly joined to theaccess tube.
 3. The medical device insertion apparatus of claim 1wherein the retention portion includes a first wing and a second wing.4. The medical device insertion apparatus of claim 3 wherein theovertube includes a first slot and a second slot and wherein, when theretention portion is in its second configuration of increased lateralextent, the first wing is receivable within the first slot and thesecond wing is receivable within the second slot.
 5. The medical deviceinsertion apparatus of claim 1 wherein the overtube includes a retentionportion disposed at a distal end of the overtube and wherein theretention portion of the overtube is reconfigurable between a firstconfiguration of reduced lateral extent and a second configuration ofincreased lateral extent.
 6. The medical device insertion apparatus ofclaim 1 wherein the first sheath includes a connector and wherein thesecond sheath includes a connector, the connector of the first sheathcouplable with the connector of the second sheath.
 7. The medical deviceinsertion apparatus of claim 6 wherein the first sheath includes asecond connector, the second connector of the first sheath disposeddistally of the first connector of the first sheath, and wherein thesecond connector of the first sheath is couplable with the connector ofthe second sheath.
 8. The medical device insertion apparatus of claim 1wherein the retention portion is configured in the second configurationof increased lateral extent by moving the second sheath distally withrespect to the first sheath.
 9. The medical device insertion apparatusof claim 1 wherein the overtube has a distal end, and wherein the distalend is tapered.
 10. The medical device insertion apparatus of claim 1wherein the overtube has a distal end, and wherein the distal end has acircumferential groove.
 11. A method of inserting a medical device intoa patient comprising the steps of: inserting a trocar and access tubethrough a body wall of the patient, wherein the trocar is disposedwithin the access tube and wherein a retention portion disposed at adistal end of the access tube is configured in a first configuration ofreduced lateral extent; configuring the retention portion in a secondconfiguration of increased lateral extent; inserting an overtube aroundthe access tube and through the body wall, wherein the access tube isreceived within a central lumen of the overtube; advancing the overtubeover the retention portion; configuring the retention portion in thefirst configuration of reduced lateral extent; withdrawing the trocar;withdrawing the access tube; and inserting the medical device within thecentral lumen of the overtube and through the body wall.
 12. The methodof claim 11 further comprising the step of coupling the trocar to theaccess tube prior to the step of inserting the trocar and access tubethrough a body wall of the patient.
 13. The method of claim 11 whereinthe access tube includes a first sheath and a second sheath and whereinthe step of inserting the trocar and access tube through the body wallof the patient includes the steps of rigidly coupling the first sheathto the second sheath and rigidly coupling the trocar to the access tube.14. The method of claim 11 wherein the access tube includes a firstsheath and a second sheath and wherein the step of configuring theretention portion in a second configuration of increased lateral extentincludes the step of moving the second sheath distally with respect tothe first sheath.
 15. The method of claim 11 wherein a retention portionis disposed at a distal end of the overtube and further comprising thestep of configuring the retention portion of the overtube in aconfiguration of increased lateral extent after the step of insertingthe overtube around the access tube and through the body wall.
 16. Themethod of claim 11 wherein the medical device is a gastro-intestinaltube.
 17. The method of claim 11 wherein the body wall includes anabdominal wall and a gastric wall.